Ecological Risk and Early Warning of PCBs in Central Jilin Province's Black Soil Zone, China

To investigate the levels of polychlorinated biphenyls (PCBs) in the black soils of Northeast China, we collected 59 surface soil samples from the central black soil region of Jilin Province. We analyzed the concentrations and sources of seven PCBs in the black soil, assessed the ecological risks associated with PCB contamination, and provided a risk assessment for PCBs in this soil type. The mean concentrations of the seven PCBs (PCB28, PCB52, PCB101, PCB118, PCB138, PCB153, and PCB180) were as follows: 1.61 μg/kg, 10.61 μg/kg, 0.37 μg/kg, 4.11 μg/kg, 0.70 μg/kg, 1.07 μg/kg, and 2.09 μg/kg, respectively. Principal component analysis revealed that PCB contamination in black soil is mainly attributed to automobile exhaust emissions during transportation, waste incineration processes, and insulation materials from electronic and electrical equipment. PCB28 and PCB52 are the primary causes of PCB danger, according to the findings of the ecological risk assessment, with Liaoyuan City having the highest risk. By applying contemporary industrial economic theory to analyze the annual accumulation of contaminants, we forecasted future PCB concentrations in black soil and issued a risk warning for these seven PCBs. Our results indicate that under the three scenarios considered, the presence of these seven PCBs in black soil does not pose a significant risk. However, given that our study examined only seven PCBs, the actual environmental risk may be underestimated.